1. Field of the Invention
This invention concerns generally a method and/or system for use in rotary-type well-drilling operations. More specifically, it concerns a method for determining porosity of a formation from drilling response.
2. Description of the Prior Art
In the past, there have been some suggestions for obtaining data as a well is drilled and making a record thereof. Such suggestions purport to obtain such data in various ways. For example, there is an article titled "The Drilling Porosity Log (DPL)" by William A. Zoeller, which was the subject of a Society of Petroleum Engineers of AIME paper number SPE-3066. However, such past efforts have not proved practical in producing useful results.
On the other hand, a U.S. Pat. No. 3,916,684 issued Nov. 4, 1975 has disclosed a practical invention for developing a surface drilling log which indicates a formation parameter as described therein. By adding to that invention a torque measurement and by applying the concepts of this invention, a porosity logging method according to this invention may be defined.